Remove dead code from MipsPassConfig

[kimgr]

Summary

Found by GCC's -Wunused-function

[atanasyan]

LGTM
Do you have commit access?

[kimgr]

I do not, could you commit it for me? Thanks!

[atanasyan]

Thanks for the patch.

llvm/trunk/lib/Target/Mips/MipsTargetMachine.cpp

public:
   const MipsSubtarget &getMipsSubtarget() const {
     return *getMipsTargetMachine().getSubtargetImpl();
   }
 
   void addIRPasses() override;
   bool addInstSelector() override;
   void addPreEmitPass() override;
   void addPreRegAlloc() override;
-  void addPreEmit2() ;
   bool addIRTranslator() override;
   bool addLegalizeMachineIR() override;
   bool addRegBankSelect() override;
   bool addGlobalInstructionSelect() override;
 };
 
 } // end anonymous namespace
 
if (Subtarget->allowMixed16_32()) {
     // FIXME: This is no longer necessary as the TTI returned is per-function.
     return TargetTransformInfo(F.getParent()->getDataLayout());
   }
 
   LLVM_DEBUG(errs() << "Target Transform Info Pass Added\n");
   return TargetTransformInfo(BasicTTIImpl(this, F));
 }
 
-void MipsPassConfig::addPreEmit2() {
-}
-
 // Implemented by targets that want to run passes immediately before
 // machine code is emitted. return true if -print-machineinstrs should
 // print out the code after the passes.
 void MipsPassConfig::addPreEmitPass() {
   // Expand pseudo instructions that are sensitive to register allocation.
   addPass(createMipsExpandPseudoPass());
 
   // The microMIPS size reduction pass performs instruction reselection for